Improved apparatus and process for the manufacture of salt



tnitd giant tmf vite JOB A. 'Davison WATER-TOWN, -NE-W YORK.

Letters Patent No. 93,066, dated July 27, 1869.

IMPROVED APPARATUS AND PROCESS FOR THE MANUFACTURE OF SALT.

The Schedule 4referred to in these Letters Patent and makirngpart of the Sme.

To all whom it may concern salt, or for evaporating the water from the cane (or other) juice in the manufacture of sugar, or forl similar pui'poses,\vl1ere it is required to separate the material held in` solution from the liquid in which itis dissolved.

lhey consist in al newprocess. and in a means 0r i apparatus for practising s'nchprocess, hereinafter more fully set forth; and I shall describe them as applied to the manufacture of salt from brine,for which I have more particularly designed them, although applicable,- also, to other kindred purposes.

Heretofore, in the salt-manufacture, the practice has been to supply the ordinary kettles with the cold brine,

iirst properly prepared, and then by heating these kettles, or a series of them, to the requisite temperature, and for a sufficient period, the water is evaporated from the sait. vBut to this mode of treatment there are many and serious objections,\ among' which may be enumerated the following, viz: the impurities are not removed, but remain with the salt; the frequent emptying of each kettle of its contents, and filling it with cold brine, involves a greatloss of heat and fuel, and damages the kettles there 'is no regular or even temperature preserved in the series of kettles; there are no means in the apparatus employed for removing any of the impurities before the brine is put into the evaporatingkettles; there are no means for concentrating and utilizing the hulk of the heat generated by the furnace, or of applying it so that a greatly-increased heating-sur'-A face is obtained, without any increase inthe consumption of fuel.

NOW, to remedy'thes'e and othrerexisting defects, my

' improved process consists in purifying the brine by heating, and then supplying the evaporating-kettles with this already-heated and purified brine, 'the heat -for-both purposes vbeing supplied from the same fur-- nace or heating-apparatus; and my improved apparatus consists in an evaporating-kettle, so constructed and applied as to serve also as a fire-back to the firechamber; in an evaporating-kettle constructed with deep longitudinal corrugations, troughs, or hollow ribs or chambers, for receiving and holding the brine, and for receiving and concentrating the heat v011 the under side; also,l in purifying-kettles, havingsimilar ribs or chambers,.and communicating-passages, to give a long route ory passage from the. irstito the last of such chambers, and an outlet, to discharge the ibrine into the next in series of the purifiers, oninto, the evaporating-kettles; and in' certain details bf construction hereinafterdescrihed.

Figure 1 represents a longitudinal section of a baseburning furnace, with my improvements applied thereto.

Figure 2 is a top view of the same, partly'insection, as indicated by the lines w a', in fig. l, in order to show the construction of the grate.

Figure 3 is a front view of v he furnace andthe gratebars, and the means for rocking the latter.

Figure 4 represents modications in the modeof con'- structing the evaporating and purifying-kettles.

Figure 5 represents a side view, and also a central cross-section of one of the-grate-hars.

'A is a furnace, made of s iicient length to contain i the evaporating-kettles B B, and a series of sets of purifying-kettles or chambers, O, one set only of the latter being exhibited in thedrawing. V

D is a feed-chamber for fuel. E is the grate, 'and F, the smoke-pipe.,

G is a hinged or swinging deflector, such as I use to vary the current of the hot air passingpfrom the fire and beneath the vessels Br or C.

'H-Jis a rod connecting the grate-bars, and

' I, a cross-bar, in which the rear ends of 'the ate- -bars rest, so as to be rocked, and also to be with rawn when desired.

K represents a series, of fixed rods or bars, f, formingthe front of the fire-chamber of the furnace.

L is ahinged or movable top or cap tothe feed-chamber D.

` The evaporatin'g-trough, or kettle or kettles B, as

`well as the evaporating-kettles B', and-the purifyingkettles C, I makeof castiron,.or other suitable metal adapted for the special purpose in view, and of about the form shown in cross-section, in fig. 1, the kettle-B vbeing so located that one side of it forms the fire-back of the fire-ch amber, thus not onlysuperseding anybrickwork atthat point,but greatly economizing and ntil-v izing the heat, which'tlius actsfat once and almost directly upon the brine contained in B. This kettle may also, if desired, extend around both ends as well as across theback of the iire-poththus still further economizing and utilizing'the heat generated. It should preferablyv be made distinct from the longitudinallylibbed or corrugated kettles .B B', and should-be made so as-to' be removable as readily as any ordinary kettle.

The kettles B B', I make of similar form with B, in cross-section, and either make the whole of theniin one piece, or, for greater facility of substitutionfand repair, Vinv sections, somewhat as shown in figue, the

sections being bolted or secured together, their ends being closed by cross-castings or pieces I) b. This construction, and the placing of the ribs ortroughs as shown, lengthwise of the furnace, gives not only a very great heating-surface, in proportion to the size of the furnace and quantity of brine to be evaporated, but also concentrates and compacts the heat into the arched passages tln'ough which it must go in its coursethrough the apparatus. g

The purifyingtroughs G are in construction similar to tbe kettles B', but they are placed at a higher elevation, that they, or rather the lastof the set, may discharge their contents so as to supply these kettles with lpurified brine; and each compartment C of each set has a channel, d, at one end, communicating with the top of the next compartment, these channels beingA so located alternately', first at one end and then at the other, as toV cause the brine which is being purified t0 take the slowest and most circuitous route possible, be-

` fore being discharged into the next set of purifyingkettle/s, or into the evaporating-kettle or kettles, as the case may be, thus insuring the deposit into the removable pans, (not necessary to be sho\vn,) which are placed at the bottom of the `purifying-trougl1s, of the impurities with which the brine is more or less charged, such pans being from time to time, as may be needful, lifted from the troughs and, emptied. The purifying and evaporating-kettles need not be removedexcept,for repairs.

Each set of ,purifyin g-troughs has an inlet, by which brine is supplied to the first of' its series of troughs, and 'an outlet, as shown at e, by which it discharges the purified brine, the thoroughness of the purification varying with the number of purifiers employed; anda strainer is preferably placed over each outlet-pipe, to prevent impurities passing to the, next purifier' or kettle.

Then the brinel is being heated, these inlets.y and outlets are stopped, by any stop-cock or appropriate device, until it is heated to the desired or ascertained proper temperature, (a thermometer being appropriately used for this purpose,) after which a constantv fiow is kept up, sufficient to supply the evaporatingkettles. In the latter, the liquid is allowed te' rise above the tops of the ribs or corrugations, the sides and ends of the compartment containing them being made high enough above them to allow of this, thus affording a larger evaporating-surface for the brine or other material.

It will be observed that the front gratings fare fixed, and that there is no door capable of being opened inimediately near the burning fuel. In this way I avoid the sudden reduction of' heat of the fire, incident to all stoves or furnaces whose doors are frequently opened for the supply of fuel, and for other purposes, the fuel, in my apparatus, being supplied at y, the covering of which may be closed as desired.

lVhile, by means of the handle 71., the bars of the fire-grate may all be rocked upon'their separate bearings, the removable nuts i i afford a provision by which any orall of the bars may beremoved for substitution or repair. The grate-bars are preferably made fiat on their tops, and narrower on their under side, as seen yin cross-section, in fig. 5, the latter feature preventing any clogging with coal, cinders, &c., and readily freeing the interspaces, when the grate is riddled by means of handle h.

I claim- 1. The process, substantially as described, of purifying and evaporating, by supplying the evaporatingkettles with the liquid already heated and purified, by means of the same heater which heats such kettles.

2. An evaporating-kettle, so constructed andapplied as to serve also as a fire-back tothe fireclnunber, substantially as described. p

3. An evaporating-kettle constructed with longitudinal corrugations or hollow ribs, for rec`eiying heat., and corresponding ones for containing'the liquid to be evaporated, substantially as described.`

4. A purifying-kettle having ,corrugations or ribs, as last uamed, and communicating-channels, to give a long route or passage from the first to the lastchamber thereof, anda discharging-outlet, substantiallyasdescrihed.

5. The combination ofthe fixed grating f with the movable grate-bars, arranged to receive a rocking motion iu their bearings, substantially as described.

6. The combination of the adju table heat-deflcct' ors G with the corrugated troughs, ubstantially as described.

7. The construction, in an evaporating-apparatus, of the fire-chamber and its feed-chamber, so that the fuel may be supplied without opening any door directly admitting cold air to the ignited fuel,'substantiallyas described.

. J. A. DAVIS. Witnesses:

JOHN J. HALSTED, FRANK HAMILTON. 

